The present invention relates to a computer-used switch structure of contact points of shift switch and contact portions of circuit board. The switch structure includes an elastic contact plate disposed under the shift switch and having projecting contact points for contacting with corresponding conductive contact portions of the circuit board. A slope slot is formed between each two adjacent contact portions to separate the contact portions from each other and avoid detachment and scattering of the conductive material of the contact portions, which may make a short circuit, caused by long term of reciprocal sliding of the contact points between the contact portions.
A conventional computer-used switch structure mainly includes a contact roller coated by a layer of carbon paste and disposed under the switch, whereby the contact roller reciprocally rolls on the carbon paste-made contact portions of a printed circuit board to changingly make the circuit. In such switch structure, the contact roller is quite expensive and a relatively great force is necessary for shifting the switch. FIGS. 1 and 2 show another type of conventional computer-used switch structure, wherein a separating membrane 13 is located between the switch and the circuit board 15 printed with electronic circuit 14. The separating membrane 13 is formed with contact slots 12 in alignment with contact points 10 printed on a contact membrane 11. The separating membrane 13 is sandwiched between the circuit board 15 and the contact membrane 11, permitting the contact points 10 to contact with the contact points 141 of the electronic circuit 14 of the circuit board 15. When the shift switch 20 covering the contact membrane 11 is shifted to depress the conductive contact points 10, the same pass through the slots 12 to contact with the contact points 141 of the circuit board 15 and make the circuit. At this time, the adjacent contact points are kept insulated. Such switch structure is widely used. However, several shortcomings still exist therein as follows:
1. It is troublesome to assemble the contact membrane 11 with the separating membrane 13 and it often takes place that only one of the two membranes is mounted in the switch (with the other neglected) by human incaution. PA1 2. It often takes place that the two membranes are mounted in an incorrect position. PA1 3. The intermediate separating membrane is made by additional molds and materials. This increases the manufacturing cost and time. PA1 4. The switch structure is composed of more components so that the assembling cost is increased.
Accordingly, the above two conventional switch structures are both not ideal and the quality thereof cannot be ensured. Therefore, it is necessary to provide a more reliable and more economic computer-used switch structure to eliminate the above problems.